/*
 * $URL: https://dnsprobe.googlecode.com/svn/trunk/dnsprobe/src/dnsprobe/resolver/Nameserver.java $
 * 
 * Copyright (c) 2009, Anonymous
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Anonymous nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY ANONYMOUS ''AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL ANONYMOUS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */

package dnsprobe.resolver;

import java.net.InetAddress;
import java.net.UnknownHostException;

import org.xbill.DNS.AAAARecord;
import org.xbill.DNS.ARecord;
import org.xbill.DNS.Lookup;
import org.xbill.DNS.Name;
import org.xbill.DNS.Record;
import org.xbill.DNS.Resolver;
import org.xbill.DNS.SimpleResolver;
import org.xbill.DNS.TextParseException;
import org.xbill.DNS.Type;


/**
 * Loest Namen ueber einen Nameserver auf
 * 
 * Da man bei der behinderten dnsjava-Implementation an keiner Stelle den 
 * Resolver vorm lookup einzeln per Hand umbiegen kann, darf ich die scheisse 
 * hier wieder zu Fuss machen.
 * 
 * CODE REUSE MOTHERFUCKER, DO YOU KNOW IT?
 * 
 * @author BerndBernhardson
 * @author anon004
 * @author snoop
 * @version $Id: Nameserver.java 91 2009-07-01 14:56:26Z bernhardson@gmx.net $
 *
 */
public class Nameserver
{
	/**
	 * der momentane Resolver
	 */
	private Resolver resolver;
	
	/**
	 * Konstruktor
	 * 
	 * @param nameserver Die Adress des Nameservers ueber den aufgeloest werden soll
	 */
	public Nameserver(final String nameserver)
	{
		try
		{
			resolver = new SimpleResolver(nameserver);
		}
		catch(UnknownHostException e)
		{
		}
	}
	
	/**
	 * Konstruktor
	 * 
	 * @param resolver Der Resolver ueber den aufgeloest weredn soll
	 */
	public Nameserver(final Resolver resolver)
	{
		this.resolver = resolver;
	}
	/**
	 * Aendert den Resolver
	 * 
	 * @param resolver Der neue Resolver
	 */
	public void setResolver(final Resolver resolver)
	{
		if(resolver == null)
		{
			return;
		}
		
		this.resolver = resolver;
	}
	
	/**
	 * Sagt ob ein Resolver zugewiesen ist
	 * 
	 * @return Ob ein Resolver zugewiesen ist
	 */
	public boolean hasResolver()
	{
		return (resolver != null);
	}
	
	/**
	 * loest einen Hostnamen auf
	 * 
	 * oest einen Hostnamen auf und liefert alle gefundenen A- oder AAAA-Records
	 * 
	 * @param host Der Hostname
	 * 
	 * @return Die gefundenen Adressen
	 * 
	 * @throws UnknownHostException Wenn der Hostname ungueltig ist oder keine A- oder AAAA-Records gefunden wurden
	 */
	public InetAddress[] lookupAllHostAddr(final String host) throws UnknownHostException
	{
		final Name name;

		try
		{
			name = new Name(host);
		}
		catch (TextParseException e)
		{
			throw new UnknownHostException(host);
		}

		Lookup   lookup;
		Record[] records = null;
		
		lookup = new Lookup(name, Type.AAAA);
		lookup.setResolver(resolver);
		records = lookup.run();
		
		if(records == null)
		{
			lookup = new Lookup(name, Type.A);
			lookup.setResolver(resolver);
			records = lookup.run();
		}

		if(records == null)
		{
			throw new UnknownHostException(host);
		}
		
		final InetAddress[] result;
		
		result = new InetAddress[records.length];
		
		for(int i = 0; i < records.length; i++)
		{
			if(records[i] instanceof ARecord)
			{
				final ARecord record;
				record = (ARecord)records[i];
				result[i] = record.getAddress();
			}
			else
			{
				final AAAARecord record;
				record = (AAAARecord)records[i];
				result[i] = record.getAddress();
			}
		}
		
		return result;
	}
}
